Rush to the stone barrier behind the human barbecue (A) and press on it. Enter the passageway, run north, and climb up the staircase to find the red key (B). Backtrack to the pool of brown slime and run west. Go downstairs, and run to the red door in the northeast. Open it, and go through the passageway to a large room (C) with a pool. Run south, and flip the switch at the southeast to open the upper windows (D); be careful, however, of the enemies revealed as a result. Retrace your steps to the brown slime pool, and do a running jump through the eastern window onto the stone stairway (E). Make sure you are standing far away before doing so, or the jump will fail. Go around to the southwest and grab the yellow key (F). Backtrack to where you found the red key, and open the yellow door. Jump over to the northern walkway (H), and make your way to the southwest. Open the door, and hit the exit switch.

Upon stepping onto where the yellow key sits, an alcove will open nearby containing a computer map (I). (sector 114)

At the northeast of the room where you find the yellow key, on a lowered platform, there is a blue key (G). Grab the key, and jump back onto the stone walkway. On the wall south, there is a misaligned section of wall (J). Go to this wall and open it to find a green stone room (K) with a switch. (sector 126) Press it to trigger a lift leading to a teleporter (L). Enter it to find passageway (M) with a box of shells and a rocket. Make your way to the soul sphere; the walls will lower to reveal a set of enemies on teleport pads (N), as well as two medikits, a box of ammo, a box of shells, and a weapon on the sole white teleporter pad (a chaingun on Hey, Not Too Rough or lower, a super shotgun on Hurt Me Plenty or higher). There is a set of skull switches (O), four of which open teleporters allowing you to telefrag the hellspawn; the one at the north of the eastern wall opens one leading to the southwest pad; the one at the center of the eastern wall opens one leading to the northeast pad; the one on the east of the southern wall opens a teleporter leading to the southeast pad; and the one at the west of the southern wall opens a teleporter taking you to the central pad. The switch at the south of the eastern wall lowers the white pad (P); after the enemy walks off, you can then grab the weapon sitting on it, but you must do so before the pad rises again. You can make as many attempts as you want, however. On Hey, Not Too Rough or lower, the enemies are all shotgunners (with one pad empty); on Hurt Me Plenty, the pads are occupied by four imps and a baron of Hell; and on Ultra-Violence or higher, the pads hold two Hell knights and three barons.

On your way to the exit, the grey brick alcove contains a switch (Q). Flip this, and backtrack to where you found the red key, opening the green stone closet in the north. Run in to find a teleporter (R) that leads to the tower in the center of the yard (S), where you can obtain a soul sphere. (sector 66)

The brown alcove near the exit (T) can be jumped into. Once you do this, open the misaligned wall in the south (U) to find either ten armor bonuses (on Hey, Not Too Rough or lower), security armor (on Hurt Me Plenty), or combat armor (on Ultra-Violence or higher). (sector 153) In the Sony PlayStation version, the platform is also accessible through a door to its west marked by a misaligned wall, likely to make it easier to access on the PlayStation controls.